Hatchet extension for micrometers



L. LOWENSTEIN.

RATCHET EXTENSION FOR MICROMETERS.-

APPLICATION HLED MAY I6; 1918.

1,308,988. Patentd July 8, 1919,

' I 7 814mm xvi/mm Louisloweyfely, g2 Q Q .w

Tm: COLUMBIA KLANOQRAPH co.v WASHINGTON, n. C.

LOUIS LOWENSTEIN, OF DETROIT, MICHIGAN.

RATCHET EXTENSION FOR MICROMETERS.

Specification of Letters Patent.

Patented July 8, 1919.

Application filed May 16, 1918. Serial No. 234,864.

To all whom it may concern:

Be it lmown that .I, LOUIS LOWENSTEIN, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Ratchet Extensions for Micrometers, of which the following is a specification, reference being had therein to the accompanying drawings.

Owing to the peculiar manner in which a micrometer gage is held in the hand when making measurements, it is extremely difficult to adjust the same, particularly the ratchet mechanism, which ordinarily is a reduced portion of the micrometer gage. To permit of the ratchet mechanism being easily and quickly adjusted is the main object of my invention, which is accomplished by providing an extension that may be easily fitted over the ratchet mechanism and the outer end of the micrometer barrel, so that the fingers of the hand holdin the gage may conveniently rotate the rate et.

The mechanical construction entering into my invention will be hereinafter considered and then claimed, and reference will now be had to the drawings, wherein- I Figure 1 is a side elevation of a micrometer gage provided with a ratchet extension in accordance with my invention;

Fig. 2 is an enlarged longitudinal sectional view of the ratchet extension as applied to the ratchet mechanism of'the gage, and

Fig. 3 is a sectional view taken on the line IIIIII of Fig. 2.

In the drawing, there is shown a conventional form of micrometer gage as comprising a barrel 1, a U-shaped arm 2, a fixed anvil 3, an adjustable spindle 4, a locking nut 5, a ratchet mechanism 6, and a knurled finger piece 7 by which the ratchet Inechanism and the spindle 4 are actuated. By

rotating the finger piece 7 the spindle 4 may be adjusted against a piece of work and to prevent excessive pressure being brought to bear upon the piece of work by the spindle 4.. the ratchet mechanism allows the finger piece 7 to revolvefreely of the spindle 4, before excessive pressure can be brought to bear on the piece of work by said spindle.

It is on the finger piece 7 that I mount an extension, comprising a sleeve 8 having knurled portions 9. The sleeve 8 provides clearance for the end of the barrel 1 and the outer end of said sleeve has a convexoconcave end wall 10 to which its connected, by a rivet 11 or other fastening means, an inwardly projecting thimble 12. The thimble 12 is concentric of the sleeve 8 and has the side walls thereof provided with longitudinal slits or slots 13 that permit of the walls of the thimble being sprung to engage over the finger piece 7 and frictionally grip the same, so as to establish rotative continuity between the sleeve 8 and the finger piece 7.

In splitting the walls of the thimble a plurality of arms are formed and each arm has its free end inbent or bowed so that the extension sleeve may readily engage micrometers having finger pieces of slightly differ ent diameters.

It is now apparent that the sleeve 8 provides a large finger-piece or handle by which the spindle 4 may be easily and quickly adjusted by the fingers of the hand holding the micrometerand as the sleeve 8 is detachable relative to the finger piece 7 the extension may be manufactured as an accessory and used in connection with micrometer gages already in use.

What I claim is 1. An extension for the finger piece of a micrometer gage comprising a sleeve having one endthereof closed, and an inwardly, projecting slitted thimble carried by the closed end of said sleeve and adapted to be fitted over the finger piece of the micrometer gage.

2. The combination with a micrometer gage having a ratchet mechanism provided with a finger piece, of an extension sleeve loose about the inner end of said gage, and a friction split thimble carried by said sleeve and engageable with said finger piece, whereby upon the operation' of said extension sleeve movement will be imparted to said ratchet mechanism. v

In testimony whereof I affix my signature in the presence of two witnesses.

noUrs'LowENsr-EIN.

Witnesses: I

KARL H. BUTLER, ANNA M. DORR.

Copies of this patent may be obtained for live eents each, by addressing the Commissioner of Patents, Washington, D. 0. g 

